This invention relates generally to curvilinear support devices and their methods of manufacture. More specifically, this invention relates to pipe support cradles and the like that are lined with a polyurethane elastomer that is applied by a bulk injected, centrifugally spin casted technique.
There is a continuing need for lining angular and curved types of support structures; for example, for lining the interior surfaces of fluid carrying pipes and for lining the concave surfaces of support cradles. Ideally the lining not only would be rugged with great wearability, but it would be manufactured onto the pipe or cradle in a manner suitable for high volume, yet inexpensive, production.
Prior art proposals have suggested the use of polyurethane foams or fibrous insulating materials as interior linings or exterior jackets. These lining materials are cellular in composition and therefore have the shortcoming of not being highly wear-resistant. The suggestions for manufacturing such support structures have included individually wrapping, molding, spraying, or pouring a coating onto each support unit. These techniques of manufacture have the shortcoming of not being conducive to high volume, inexpensive production.
There have been proposals for lining the inner surfaces of pipes by using spin casting techniques. One proposal has suggested applying a polyimide lining to a pipe interior by means of centrifugally spin casting the polyimide onto the surface. Another proposal has suggested the spin casting of a wear-resistant polyurethane elastomer onto the inside pipe surface, such as for use on a slurry line.
Although such spin casting techniques have provided wear-resistant coatings on interior surfaces, the proposals have not been adapted for high volume, batch production of curvilinear support cradles having an open, concave surface lined for wearability.